1. Technical Field
The present disclosure relates to an optical lens assembly, and more particularly to a compact optical lens assembly.
2. Related Art
In recent years, the optical lens assembly is used in a variety of application fields, especially in mobile phones, webcams, cars, surveillance cameras and electronic entertainment industries. The photo-sensing device, e.g. a sensor, of an ordinary optical lens assembly is commonly selected from a charge coupled device (CCD) and a complementary metal-oxide semiconductor (CMOS). In addition, as the advanced semiconductor manufacturing technology enables the miniaturization of pixel size of sensors, the resolution of a compact optical lens assembly is gradually increased. Such improvement leads to demands for compact optical assemblies featuring the ability of forming high-quality image on an image sensor.
A conventional camera lens used in mobile phones usually consists of three lens elements. In U.S. Pat. No. 6,490,102, for example, an optical lens system for taking image which consists of glass and plastic lens elements is disclosed. In the optical lens system, the third lens element is a spherical glass lens element. However, the spherical glass lens element reduces the freedom available for correcting the aberration of the optical lens system, which makes the camera lens more difficult to control the image quality.
Moreover, U.S. Pat. No. 7,262,925 discloses an image lens array consisting of three lens elements, wherein the stop is disposed between the first lens element and the second lens elements. Hence, the optical length of the image lens array is increased, which does not meet the demand of having a compact image lens array.